Ground-terminal connection for electric conductors.



L. B. BUCHANAN.

GROUND TERMINAL CONNECTION FOR ELECTRIC CONDUCTORS. APPLICATION FILED wuz 4. 1915.

1,167,378. Patented 52111.11, 1916.

unirn snare-s rarnnr orrion LEONARD B. BUCHANAN, OF WOBURN, MASSACHUSETTS.

GROUND-TERMINAL CONNECTION FOR ELECTRIC CONDUCTORS.

Application filed June 4, 1915.

To (ZZZ whom it may concern:

Be it known that I, LEONARD B. BUCHANAN, a citizen of the United States, residing at lVoburn, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Ground-Terminal Connections for Electric Conductors, of which the following is a specification.

In grounding electric conductors it is com mon to attach the electric conductor to a water or other pipe, which forms the ground terminal. Safety demands that this connection shall be good and permanent, and the underwriters-so require. Hitherto it has been common to solder the electric conductor to a specially made terminal piece, clamped around the pipe. VVindingthe conductor around the pipe, without soldering, is simple, but has been found unreliable, as the coils, even if tight at the start, tend to uncoil themselves and work loose, in the absence of an effective clamp, and the strength of the wire is lessened at the twist if a really good contact is secured; furthermore, it cannot practically be tightened or be easily disconnected.

My invention is a new form of ground connection, consisting of a novel combination of the end of the electric conductor, with a clamping and locking mechanism, which is simple, cheap and readily applied by workmen of slight skill, and which is durable, and yet readily attached, and equally readily, tightened or disconnected, and if desired reapplied in another place.

As stated, the electric conductor is itself used as the pipe-embracing portion of the ground connection, and in accordance with my invention, must be formed of a heavy wire, flexible, but yet sufficiently rigid to hold its shape after being attached. I have found a copper wire, about it of an inch in diameter, to be very satisfactory for this purpose. This wire conductor is turned back upon itself to form a loop, the double portion being of sufficient length to be bent to form a bend for engagement with one end of the clamping-device, and have its loop-portion carried around the pipefar enough to engage with the other portion of the clamping-device, as hereinafter provided. The clamping-device may consist of a hook-portion to engage the bend in the conducting wire above referred to, and a portion extending from said bend-engaging Specification of Letters Patent.

the pipe.

Patented Jan. if, 1916.

Serial No. 32,213.

portion through the loop, this portion of the clamp being threaded to receive a nut, so that the loop may be tightly clamped around the pipe, thus making and maintaining a good electrical connection.

Figure l is a side-elevation of an attaching-means for attaching an electric conductor to a pipe, embodying this invention. Fig. 2 isa bottom plan view of the same. Fig. 3 is an end view. Figs. 4:, 5, and 6, are views illustrating the method of bending the conductor to form an embracing portion for Figs. 7, 8, 9, and 10 are modifications to be referred to.

1 represents the pipe adapted to be used as the ground terminal, and 2 the bared-end portion of the wire conductor which, as stated, is preferably made of copper wire of about it; of an inch in diameter, from which 1 form the ground connection. Said bared end-portion of the conductor, (see Fig. 4:) is reflexed as in Fig. 5, and the refiexed portion is bent around the pipe to form the pipe-embracing portion, which constitutes the electrical connection with the ground. A loop or eye is formed at l, and a bend 5, at the other end of the pipeembracing portion. A clamping device is employed, having a bend-engaging and a threaded portion; the bend-engaging portion is arranged to engage the bend 5 and the threaded portion passes through the eye 4; a nut is placed on the threaded portion and is turned until it bears firmly against the loop and so draws the bend and eye tightly together, so as to draw the pipe-embracing portion into firm engagement with the pipe. One form of clamping device here shown consists of a bolt, having at one end a hook 10 (see Fig. 2), or it may be a T- shaped head 14 (see Fig. 7), for engagement with the bent portion of the wire conductor, and a threaded shank portion, adapted to extend through the loop or eye 4, receiving at the other sidethereof a nut 16, preferably with a washer 17. Obviously, the tightening up of this nut in the usual manner will draw the two end-portions of the pipe-embracing portion of the wire conductor together and cause them to embrace the pipe snugly. It is obvious that with this construction both strands of the wire conductor are held firmly against the pipe, and there is no tendency to unwind, such as exists in the case of an ordinary series of case where a double strand is used.

windings around a pipe, and such spring strain as the copper wire exerts tends to hold the nut firmly in place upon the bolt and prevent slipping. I consider this use of a double strand important, but my invention in certain aspects includes an inferior construction, shown in the drawing, Fig. 9, in which but a single strand of wire is used as the wire-embracing portion which is bent at 5, to form a bearing for one end of the clamping device, and at 4:, to form the loop through which the threaded shank portion of the clamping device may be passed, and the whole device may then be passed around the pipe and clamped into position, as in the In this latter construction an ordinary stovebolt (see Fig. may be used as the clampin -device.

In both constructions it is obvious that the clamping portion may be reversed in position, but I prefer to use it as hereinbefore described, that is, with its headed portion at the bend 5, and the threaded portion passing through the loop 4, rather than the other way around.

The shank should be of substantial length and rovided with a long threaded portion, to al ow not only for the varying diameters of ground terminal, but, also, for variations in the amount of bend allowed by different workmen, and other variations in application.

l. Agrounding device for electrical connections, consisting of a wire current-conducting portion, bent upon itself to form an encircling portion, encircling the ground terminal and a clamping device, consisting of a hooked portion engaging a bend in one end of the doubled strand, and a threaded portion passing through the loop formed by the bending of the strands, a bearing fitted upon said threaded portion and set up tightly against said loop, so as to hold the encircling portion in close electrical contact with said ground terminal.

. 2. The attaching-means for connecting an electric conductor with a pipe, comprising a bared end-portion of the conductor bent to form a circular embracing-portion, and a loop or eye at each end of said embracingportion arranged in alinement, and a connecting-device engaging said loops or eyes, having the characteristics of a bolt, and having its threaded-portion provided with a nut which may be tightened up to draw said end-portions together, and thus firmly clamp the conductor to the pipe.

In testimony whereof, I have signed my name to this specification, in the presence or" two subscribing witnesses.

LEONARD B. BUCHANAN.

Witnesses:

H. B. DAVIS, B. J. NOYES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

